Table 3:

Prevalence of anatomic variations of the CoW in a group of 41 preterm-at-term infants (19 born after 30 weeks' GA, 22 born before 30 weeks' GA) with normal MR imaging findings

	Preterm (>30 weeks)	Preterm (<30 weeks)	P Value
Completeness of CoW	7 in 19 (36.8%)	11 in 22 (50%)	.298
AcomA absence/hypoplasia	4 in 19 (21%)	2 in 22 (9%)	.262
PcomA absence/hypoplasia	15 in 38 (39.5%)	11 in 44 (25%)	.122
A1 segment of ACA absence/hypoplasia	0 in 38 (0%)	1 in 44 (2%)	.537
P1 segment of PCA absence/hypoplasia	2 in 38 (5.2%)	2 in 44 (4.5%)	.635
Fetal-type origin of PCA	12 in 38 (31.6%)	10 in 44 (22.7%)	.257
Transitional-configuration origin of PCA	1 in 38 (2.6%)	3 in 44 (6.8%)	.365
Bilateral fetal-type origin	10 in 12 (83.3%)	4 in 10 (40%)	.048*
Bilaterally absent PcomA	10 in 15 (66.7%)	4 in 11 (36.4%)	.129

Note:—GA indicates gestational age.

^*Statistically significant.